1898.] 



NATURAL SCIENCES OF PHILADELPHIA. 



277 



U. aculens (Morel.). 

 U. acus (Pfr.). 

 U. adnata (Pfr.). 

 U. affinis (Pfr.) [P V.]. 

 U. angustior (Wright). 

 U. arcustriata (Wr.). 

 U. assimilis (Arango). 

 U. capillacea (Pfr.). 

 U. coerulans (Poey). ' 

 U. colorata (Arango). 

 U. crenulata (Gdl.). 

 U. crystallina (Wright). 

 U. decolorata (Gundl.). 

 U. diaphana (Wright). 

 U. discors (Poey). 

 U. fibrosa (Gundl.). 

 U. jusiformis (Wr.). 

 U. garciana (Wright). 



U. heynemani (Pfr.). 



U. hidalgoi (Arango). 



U. hilleri (Pfr.) [P V.]. 



U. incerta (Arango). 



U. Integra (Pfr.). 



U. irrorata (Gundl.). 



U. macra (Wright). 



U. plumbea (Wright). 



U. producta (Gundl.). 



U. sauvalleana (Gundl.) [P V.]. 



U. scabrosa (Gundl.). 



U. thomsoni (Arango). 



U. torqiuda (Morel.). 



U. uvguiculata (Arango). 



U. ventricosa (Gundl.) [P V.] 



U. violacea (Wright). 



U. wrighti (Pfr.). 



Section Amphicosmia Pils. & Van. 



Type C. salleana Pfr., PI. XVIII, fig. 22. 



Proposed for three San Domingo species in which the columella 

 bears two spiral laruinse, both finely denticulate. 

 U. salleana (Pfr.). U. gracilicollis (Auct.). 



U. hjalmarsoni (Pfr.). I 



Genus BRACHYPODELLA Beck, 1838. 



In this genus the radula is more highly specialized than in Uro- 

 coptis and the shell generally less so, internal armature of the axis 

 being entirely absent, or limited to a weak, scarcely noticeable, 

 spiral fold above. 



The geographic range of Brachypodella includes not only the ter- 

 ritory occupied by Urocoptis, but surpasses it on all sides : in the 

 Bahamas on the north, the Virgin group on the east, the whole 

 Caribbean chain and northern border of South America on the 

 south, and west and southwest is sparsely distributed over Central 

 America and southeastern Mexico. 



The distribution of the minor groups is suggestive. The Jamai- 

 can sections form a group by themselves characterized by the ex- 

 tremely aberrant dentition as well as the modified shells. The spe- 

 cies of other islands and the mainland are decidedly less specialized, 



